Year Years
1800 31.87
1801 31.87
1802 31.87
1803 31.87
1804 31.87
1805 31.87
1806 31.87
1807 31.87
1808 31.87
1809 31.87
1810 31.87
1811 31.87
1812 31.87
1813 31.87
1814 31.87
1815 31.87
1816 31.87
1817 31.87
1818 31.87
1819 31.87
1820 31.87
1821 31.87
1822 31.87
1823 31.87
1824 31.87
1825 31.87
1826 31.87
1827 31.87
1828 31.87
1829 31.87
1830 31.87
1831 31.87
1832 31.87
1833 31.87
1834 31.87
1835 31.87
1836 31.87
1837 31.87
1838 31.87
1839 31.87
1840 31.87
1841 31.87
1842 31.87
1843 31.87
1844 31.87
1845 31.87
1846 31.87
1847 31.87
1848 31.87
1849 31.87
1850 31.87
1851 31.87
1852 31.87
1853 31.87
1854 31.87
1855 31.87
1856 31.87
1857 31.87
1858 31.87
1859 31.87
1860 31.87
1861 31.87
1862 31.87
1863 31.87
1864 31.35
1865 30.82
1866 30.3
1867 29.78
1868 29.25
1869 29.3
1870 29.34
1871 29.37
1872 29.4
1873 29.43
1874 29.61
1875 29.8
1876 29.99
1877 30.17
1878 30.36
1879 30.54
1880 30.72
1881 30.91
1882 31.09
1883 31.28
1884 31.46
1885 31.65
1886 31.83
1887 32.01
1888 32.19
1889 32.38
1890 32.56
1891 32.74
1892 32.93
1893 33.11
1894 33.29
1895 33.47
1896 33.65
1897 33.83
1898 33.65
1899 33.48
1900 33.29
1901 33.52
1902 33.75
1903 33.98
1904 34.21
1905 34.44
1906 34.67
1907 34.9
1908 35.13
1909 35.36
1910 35.59
1911 38.47
1912 38.87
1913 36.72
1914 36.3
1915 35.89
1916 35.88
1917 32.93
1918 24.44
1919 34.19
1920 36.13
1921 32.21
1922 34.63
1923 35.1
1924 34.11
1925 38.32
1926 41.42
1927 40.76
1928 42.2
1929 40.97
1930 40.29
1931 39.34
1932 36.89
1933 23.29
1934 42.5
1935 43.99
1936 45.59
1937 44.61
1938 46.21
1939 48.51
1940 46.1
1941 32.19
1942 28.79
1943 26.85
1944 33.78
1945 43.41
1946 52.71
1947 44.98
1948 52.73
1949 55.4
1950 57.59
1951 57.75
1952 58.12
1953 58.47
1954 58.83
1955 59.18
1956 59.54
1957 59.89
1958 60.25
1959 60.6
1960 60.95
1961 61.32
1962 61.68
1963 62.04
1964 62.4
1965 62.76
1966 63.1
1967 63.43
1968 63.73
1969 64.01
1970 64.29
1971 64.85
1972 65.35
1973 65.92
1974 66.44
1975 66.85
1976 67.28
1977 67.72
1978 68.16
1979 68.56
1980 68.95
1981 69.32
1982 69.6
1983 69.76
1984 69.75
1985 69.74
1986 69.83
1987 69.83
1988 69.75
1989 69.63
1990 69.57
1991 69.46
1992 68.86
1993 68.54
1994 69.68
1995 70.44
1996 71.15
1997 71.29
1998 71.36
1999 71.51
2000 71.71
2001 71.98
2002 71.85
2003 71.73
2004 71.62
2005 72.03
2006 72.45
2007 72.71
2008 72.34
2009 72.69
2010 72.82
2011 72.96
2012 73.13
2013 73.29
2014 73.47
2015 73.68
2016 73.95
2017 74.13
2018 74.31